Calculating device



July 20, 1943. W, F SHAW 2,324,957

CALCULATING DEVI CE Filed Aug. '7, 1941 ab i 1N VENTOR. F762 WML/AM 1F @HAW ATTO Patented July 20,1943

UNITED STATES PATENT OFFICE cALcULzliDnvroE one-half to Horace C. Mayers, Rocky River, Ohio Application August 7, 1941, Serial No. 405,819

Claims. This invention relates to calculating devices,

and more particularly, to rotatable dial typel calculators.

An object of this invention is to provide a relatively small and compact calculating device which provides a relatively large number of problems and answers. L

Another object is to provide a relatively siml ple and easily operable calculating device, which may be used by school children in mastering the fundamental combinations in additions, subtractions, multiplication, and division.

Other objects are to provide a calculating device having a minimum number of parts and numerals the same being easily assembled and capable of being produced at a relatively low cost and adaptable for many different numerical computations.

These and other objects will be apparent during the course of the following specication.

In the drawing forming a part of this specification:

Figure l is a plan view of one of my dial calculators, with parts broken away,

Figure 2 is a central vertical section taken on the line 2-2 of Figure 1, while Figure 3 is a broken fragmentary view of a portion of my computing chart.

My calculating device, indicated generally by the numeral II, comprises an inner dial I2 formed of suitable material such as cardboard, or any other material capable of being printed on, disposed between two similar circular dials I3a and I3b, a hollow rivet I4 having iianged A portions I5 on each end thereof serving to retain the dials together and permit them to be rotated around the rivet I4 as hereinafter disclosed.

The diameter of the inner dial I2 is slightly larger than the diameters of the cooperating dials I3a and 13b so that it projects beyond the outer margins of the dials I3a and I3b. The outer margin of the inner dial I2 is preferably provided with a series of cut out portions I6, as shown in Figure 1, which facilitate the grasping and turning of the inner dial by the lingers of the operator.

As illustrated in Figures 1 and 3 it will be observed that the inner dial I2 is provided with four concentric circular rows of numerals indicated by the numerals I1, I8, I9, and 20, the numeral Il indicating the inner row, the numeral indicating the outer row, while the numerals I8 and I9 indicate the intermediate row of numerals, A close inspection of Figures 1 and 3 will disclose that the numerals in rows Il and I9 are positioned and arranged in such a manner that each numeral of each of the rows I1 and I9 is aligned with the radius of the inner dial I2, while the numerals in rows I8 and 20 are not aligned with such radius, but are aligned with a vertical line at one side of the center of .the dials indicated by the numeral 2|.

Each of the outer dials I3a and I3b is provided with two sets of problem apertures 22a and 2212, permitting numerals on the dial I2 to be viewed therethrough, said apertures being horizontally aligned. The right hand problem aperture 22a, as viewed in Figure l, is aligned with the inner row of radially aligned numerals Il, while the left handproblem aperture 22a is aligned with the next row of numerals I8 which are not radially aligned. The combination of the horizontal disposition of the problem apertures 22a and the disposition of the numerals in rows I1 and I8 on the inner dial I2 presents the numerals constituting the problem in a horizontal alignment, thus permitting the problem to be quickly and easily read. This would not be true were the problem apertures 22a disposed at a uniform distance from the center of the dial or were the rows of numerals Il and I8 each,

radially aligned.

aligned but differ from the problem apertures 22a in being aligned with rowsof numerals I9 and 20 on the inner dial I2 It will be noticed that one of the problem apertures 22b is aligned with radially disposed row of numerals I9 and the other is aligned with non-radial row of numerals 2D.

Answer apertures 23a and 23D are also pro,- vided in dials I3a and I3b. It will be noticed that answer aperture 23a is aligned with the outer row of numerals 2U on the inner dial I2, while answer aperture 23h is aligned with next to the inner row of numerals I8, so that the answer numerals always show a numeral non-radially aligned.

Indicia indicating one of the particular problems such as addition, subtraction, multiplication, and division is printed near each group of V problem apertures, the word multiply being provided between problem apertures 22a and the word divide being provided between the problem apertures 22h. Dial I3b is similarly providied with problem and answer apertures relating to addition and substraction and operates in a similar manner, as will be readily understood.

There is a definite mathematical relationship between the problems of multiplication and division, hence these problems are grouped on the dial I3a, while a similar relationship between the problems of addition and subtraction results in their being grouped on dial I3b.

The calculating device II is used in an obvious manner'. For example, to set up the problem shown through problem apertures 22a in Figure 1, the user grasps the device between the thumb and the middle finger and rotates the inner dial l2 with the index finger, until thenumeral 8 ini dicating the multiplicand appears in the left hand problem aperture 22a,- and the numeral 4 indi-i cating the multiplier appears in the right hand i aperture 22a. The product 32 appears through the answer aperture 23a, which may be kept 'covered by a finger in order to give the user a chance to guess the answer which is disclosed through the answer aperture 23a when the ilnger is removed.

As shown in Figure 1, whenthe foregoing problem in multiplication is disclosed through the problem aperture 22a', a problem and answer in 'division is also set up, in which the numeral 63 indicates the dividend, 1 the divisor, and the numeral 9 appearing `through the answer aperture 23h represents the quotient. Thus, it will be seen by arranging the problem and answer apertures and disposing the .numerals asindicated, that a material saving of space is accomplished on the inner dial l2, for the reason that each row of numerals I1, I8, I9, and contains one of the figures of a problem, while the same numerals in rows I8 and 20 furnish the answers to the problems, and thus the same numerals serve as .problems and answers and provide for the double use of numerals and permits a material saving in the size of th dials.

The dial I3b contains problems in addition and subtraction in which the problems and answers are operated in a similar manner. The device herein illustrated is adapted to be used for many different types of computations and calculations, and thus provides-for a yrelatively wide range of uses. The space around the center of the outer dials l3a and l3b may contain advertising matter, and, as my invention can be produced at a very low cost, it is readily adapted for distribution as an advertising novelty.

If desired, only two dials may be used, and in such case all of the numerals may be placed on one side of the inner dial l2 and four or more pair of problem apertures 22a and 22h may be disposed in the one dial. Itis possible to further simplify the device by using rows of numerals l1 and i8 for both multiplication and addition, and in such case it is only necessary to place on the dial |30, the numerals associated with subtraction which appear on the dial I3b.

It will be apparent to those skilled in the art that my invention may be variously changed, used, or modified, without departing from the spirit of the invention or sacrificing the advantages thereof, and that the present embodiment of myv invention is illustrative only, and that my invention is not limited thereto.

I claim:

1.\In a computing device, a rst dial having concentric circular rows of numerals disposed thereon, the numerals in some rows being aligned longitudinally with the radius of the dial, the numerals in other rows being non-aligned longitudinally with said radius and disposed in parallel relation to numerals in said radially aligned row of numerals, and a second dial disposed across said first dial in -rotative relation and provided with at least two pairs of spaced apertures, each pair adapted to reveal the cooperating numerals of respectively diiferent problems, and an aperture associated with each pair of apertures and adapted to reveal the answer to the problem disclosed in its associated pair of apertures, said pairs of apertures and said single apertures being aligned with various rows of" numerals in order that the same numerals serve as parts of problems at certain positions of the dials and answers to problems when the dials are first dial in rotative relation and provided with at least two pairs of spaced apertures, each pair adapted to reveal the cooperating numerals of respectively different problems, and an aperture associated with each pair of apertures and adapted to reveal the answer to the problem disclosed in its associated pair of apertures, said pairs of apertures and said single apertures being aligned with various rows of numerals in order that the same numerals serve as parts of problems at certain positions of the dials and answers to problems when the dials are in other positions.

,3..1n a computing device, a first dial having concentric circular rows of numerals ldisposed thereon, and a second dial disposed across said first dial in rotative relation and provided with at Vleast two *pairs of spaced apertures, each pair adapted simultaneously to reveal the cooperatingv numerals of respectively different problems, and an aperture associated with each pair apertures and adapted to reveal the answer to the problem disclosed in its associated pair of apertures, said pairs of apertures and said single apertures being aligned with various rows of numerals in order that a numeral in one of said rows serves as part of one of said problems and another numeral in said one of said rows serves as an answer to another of said problems.

4. In a computing device, a first dial having concentric circular rows of numerals disposed thereon, and a second dial disposed across said iirst dial in rotative relation and provided with at least two sets of spaced apertures cooperable with said rows of numerals, each set comprising a pair of problem apertures and an answer aperture, each pair of problem apertures adapted to reveal the cooperating numerals of respectively different problems, and each answer aperture adapted to reveal the answer to the problem disclosed by the problem apertures of its set, said apertures of said sets being so aligned with said rows of numerals that some of said rows are to reveal the cooperating numerals of respec,

tively diierent problems, and each answer aperture adapted to reveal the answer to the problem disclosed by the problem apertures of its set, said apertures of said sets being so aligned with said rows of numerals that an answer aperture of one set and a problem aperture of another set are aligned with the same row of numerals.

WILLIAM F. SHAW, 

